Photonic acousto-optic frequency shifter

Abstract

Methods and apparatus for a photonic acoustic-optic frequency shifter having an integrated layer of lithium niobate. An input port receives input light and an acoustic wave generator generates an acoustic wave into a deflection area comprising a layer of lithium niobate. A first output port exits undeflected light from the deflection area as transmitted light and a second output port exits light deflected in frequency by the acoustic wave in the deflection area.

What is claimed is: 
     
       1. A photonic acoustic-optic frequency shifter, comprising:
 an input port to receive input light; 
 an acoustic wave generator to generate an acoustic wave into a deflection area comprising a layer of lithium niobate; 
 a first output port to exit light shifted in frequency by the acoustic wave in the deflection area; and 
 lenses, waveguides or any combination thereof after the first output port, 
 wherein the layer of lithium niobate is formed on an oxide layer. 
 
     
     
       2. The photonic acoustic-optic frequency shifter according to  claim 1 , wherein the acoustic wave generator comprises an interdigitated transducer (IDT). 
     
     
       3. The photonic acoustic-optic frequency shifter according to  claim 1 , further including a first input waveguide formed in the layer of lithium niobate to confine the input light from the input port to the deflection area. 
     
     
       4. The photonic acoustic-optic frequency shifter according to  claim 3 , further including a first output waveguide formed in the layer of lithium niobate to confine the light shifted in frequency from the deflection area to the first output port. 
     
     
       5. The photonic acoustic-optic frequency shifter according to  claim 3 , further including a first output waveguide formed in the layer of lithium niobate to confine the light shifted in frequency from the deflection area to the first output port, and a second output waveguide formed in the layer of lithium niobate to confine the input light from the deflection area to a second output port. 
     
     
       6. The photonic acoustic-optic frequency shifter according to  claim 5 , wherein one or more of the first input waveguide, the first output waveguide, and/or the second output waveguide comprises a taper. 
     
     
       7. The photonic acoustic-optic frequency shifter according to  claim 1 , wherein the oxide layer is supported by a substrate. 
     
     
       8. The photonic acoustic-optic frequency shifter according to  claim 1 , further including a sensor array to receive the light shifted in frequency. 
     
     
       9. The photonic acoustic-optic frequency shifter according to  claim 8 , wherein the sensor array comprises a focal plane array. 
     
     
       10. The photonic acoustic-optic frequency shifter according to  claim 8 , wherein the lenses, waveguides or any combination thereof are between the first output port and the sensor array. 
     
     
       11. The photonic acoustic-optic frequency shifter according to  claim 10 , wherein the sensor array comprises a focal plane array. 
     
     
       12. The photonic acoustic-optic frequency shifter according to  claim 10 , further including one or more additional photonic acousto-optic frequency shifters arranged so that optical signals from the frequency shifters have path lengths that are an integer number of wavelengths of being identical for coherent combination at the sensor array. 
     
     
       13. The photonic acoustic-optic frequency shifter according to  claim 10 , further including one or more additional photonic acousto-optic frequency shifters arranged so that optical signals from the frequency shifters have path lengths that are not an integer number of wavelengths of being identical pathlengths for non-coherent combination at the sensor array. 
     
     
       14. The photonic acoustic-optic frequency shifter according to  claim 12 , wherein the sensor array comprises a focal plane array. 
     
     
       15. A method, comprising:
 for a photonic acoustic-optic frequency shifter, employing an input port to receive input light; 
 employing an acoustic wave generator to generate an acoustic wave into a deflection area comprising a layer of lithium niobate; 
 employing a first output port to exit light shifted in frequency by the acoustic wave in the deflection area; and 
 employing lenses, waveguides or any combination thereof after the first output port, 
 wherein the layer of lithium niobate is formed on an oxide layer. 
 
     
     
       16. The method according to  claim 15 , wherein the acoustic wave generator comprises an interdigitated transducer (IDT). 
     
     
       17. The method according to  claim 15 , further including employing a first input waveguide formed in the layer of lithium niobate to confine the input light from the input port to the deflection area. 
     
     
       18. The method according to  claim 17 , further including employing a first output waveguide formed in the layer of lithium niobate to confine the light shifted in frequency from the deflection area to the first output port. 
     
     
       19. The method according to  claim 17 , further including employing a first output waveguide formed in the layer of lithium niobate to confine the light shifted in frequency from the deflection area to the first output port, and a second output waveguide formed in the layer of lithium niobate to confine the input light from the deflection area to a second output port.